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An Envisioned and Efficient Design of Next Generation Decentralized IoT Bot Detection Model
Full text linkThe Industrial Internet of Things (IIoT) and Internet of Medical Things (IoMT) are revolutionizing critical infrastructures, but their expansion has also introduced severe cybersecurity vulnerabilities. Traditional IoT Bot Detection Systems (IBDS) struggle to scale in environments characterized by high-dimensional, large-scale, and redundant network traffic. These challenges hinder the development of reliable cloud-based intrusion detection systems. The limitations of static and rulebased methods in detecting evolving IoT botnet attacks—such as those launched by Mirai and Gafgyt—underscore the need for intelligent, adaptive approaches. To address this, the present study proposes a machine learning and deep learning-driven IoT Botnet Detection Model, validated through both Hold-out and 5- fold Cross Validation techniques. The study emphasizes optimized feature selection using statistical methods like SelectKBest and correlation-based filtering to eliminate irrelevant attributes and improve model performance. The proposed model is trained and evaluated using the UCI N_BaIoT dataset—renowned for its diversity of IoT bot attacks—and further benchmarked against other leading datasets (Bot-IoT, IoT-23) to test its generalizability. Experimental results demonstrate that the model significantly outperforms three state-of-the-art detection methods across multiple evaluation metrics. In particular, the use of deep learning architectures, such as CNN and LSTM, leads to high detection accuracy while preserving computational efficiency. Feature selection not only enhances interpretability but also reduces training overhead, and SMOTE effectively addresses class imbalance. This work establishes a foundation for robust, real-time, and scalable botnet detection in IIoT environments. Future efforts should focus on enhancing adversarial robustness, deploying on edge devices, and incorporating blockchain for decentralized logging and regulatory compliance
Lactation Management Training in Graduate Nutrition and Dietetics Programs: A Preliminary Report
Full text linkThe American Academy of Pediatrics recommends exclusive breastfeeding (BF) for the first six months and continued breastfeeding for at least two years with complementary food. Despite this recommendation, only 24.9% of infants in the United States are exclusively breastfed at six months (Breastfeeding Report Card 2022). Breastfeeding support and lactation management are critical to promoting a successful breastfeeding experience. Specifically, qualified support from a Registered Dietitian Nutritionist (RDN) is recommended, yet graduate students in Nutrition and Dietetics do not receive adequate training regarding breastfeeding intervention. This study aimed to evaluate graduate Nutrition and Dietetic programs to determine the amount of exposure students/interns have to breastfeeding education, how it is delivered, and whether it includes an experiential component. A secondary purpose was to assess the program directors\u27 beliefs about the necessity of this advanced breastfeeding education and the potential barriers to inclusion in the programs. The question is whether DI programs with or without graduate courses include Medical Nutrition Therapy for interns to be equipped with the requisite skills necessary for entry-level registered dietitian nutritionists. This research was designed as a cross-sectional survey utilizing a researcher-developed questionnaire of all program directors listed in the public database of all graduate-level nutrition and dietetics programs in the program directory of the Academy of Nutrition and Dietetics (www.eatright.org). The questionnaire was distributed to 402 graduate-level nutrition and dietetic directors across the United States. There were 75 respondents. However, 18 simply opened the questionnaire without responding to any items. They were subsequently removed from the database, leaving 57 responses for this preliminary analysis. The participants included: 33 dietetic internship directors, nine coordinated program directors, 13 Graduate program directors, and two others not identified. Of those programs, 37 are part of a university/college, 10 are freestanding, nine have coordinated graduate courses or master\u27s degrees, and one was unidentified. All programs were located throughout the United States and categorized into regions: 11 in the West, 9 in the Midwest, 22 in the South, and 8 in the Northeast. Responses regarding education delivery methods in the programs indicated that 9.3% of the programs utilized distance education, 26.7% had a hybrid environment, 38.7% delivered education face-to-face, and 1.3% used other methods. When specifically asked about advanced breastfeeding and lactation management education, 57% of directors responded that students receive some breastfeeding education through a planned experience, and 12% do not receive any. When asked about the director’s expectations, 41% stated that students were not expected to deliver breastfeeding counseling, 29% said it was optional, and only 5% were expected to deliver B-Ed counseling to patients Approximately 37% of the program directors believed students gain adequate lactation management skills at the graduate level, and 50% did not believe that students receive advanced content related to lactation management. The most significant proportion agreed that students do not learn enough in this content area during undergraduate courses and need extended training. Many (46%) program directors stated that this content could not be adequately gained by learning through work experience as an RDN once practicing in the field, they also felt that students must focus on current required competencies and do not have time to prioritize specialties such as breastfeeding. Exposure to advanced education in the practice component of the program was significantly different when compared by program size. A chi-square calculation was performed, and no difference was found for didactic delivery, but a significant difference was found for practicum exposure. The smaller programs, with 1-10 students, required exposure to breastfeeding education. The larger programs, with greater than 10 students, did not require exposure to breastfeeding education, but it was optional for the student. Awareness of the breastfeeding landscape included breastfeeding rates throughout the geographical regions. Of the participants (N=57), 6.7% were not familiar with the breastfeeding rates in the U.S., 44% were slightly/moderately familiar, and 16% were very/extremely familiar. The participants were similarly asked about being familiar with BF rates in their state: 16% were unfamiliar, 37.3% were slightly/moderately familiar, and 13.3% were very/extremely familiar. Perhaps impacting decisions regarding the provision of content in the program. The results also indicated that 34.7% of participants agreed that graduate programs should develop specific lactation/BF competencies, to ensure the breadth and depth of requisite skills needed for entry-level practice as an RDN are obtained; 21.3% disagreed, and 9.3% stated it did not matter. In summary, this study indicated that vague accreditation guidance, limited program time, access to expertise, and a lack of prioritization of breastfeeding and lactation management by programs have resulted in inconsistent, minimal breastfeeding curriculum implemented throughout the programs. Future research should explore whether accreditation competencies and the programs corresponding to planned experiences involving breastfeeding/lactation should be developed with greater specificity. The programs may accomplish this development, allowing them to incorporate learning experiences tailored to their available resources. Many programs reported not implementing breastfeeding education because accreditation did not require it. Advanced breastfeeding education/lactation management should be viewed as foundational knowledge, as it is important in health promotion and disease prevention in mothers and their infants. It is not necessarily a specialty topic. Particularly in reducing overweight and obesity and other related chronic diseases, which will affect the mother and infant throughout the lifespan. Research supports successful breastfeeding experiences and increased rates following breastfeeding education. Healthcare professionals with access to mothers during this critical period should have the knowledge to support this patient/client education
Sleep, Emotion Regulation, and Relationship Satisfaction: A Moderation Analysis
Full text linkSleep plays a pivotal role in overall health and well-being, influencing mental health, cognitive abilities, memory, emotional balance, and physical well-being (Luyster et al., 2012; Mukherjee et al., 2015). Emotions constitute a natural and indispensable element of human existence but necessitate proper regulation, as any disruption in emotion control has been associated with various mental health disorders (Gross & Jazaieri, 2014; Kring & Gordon, 1998; Phelps, 2006). Furthermore, human connections and relationships are fundamental aspects of the human experience, contributing to emotional support, personal growth, a sense of belonging, and even influencing one\u27s physical health outcomes (Baumeister & Leary, 1995; Umberson & Montez, 2011). The interaction between these variables helps conceptualize the connection between our internal states, physiological states, and the quality of our relationships. Sleep plays a crucial role in regulating our emotions, affecting our mood, and influencing how we navigate interpersonal connections (Lemola et al., 2013; Weinberg et al., 2016). Additionally, emotional well-being has a profound impact on our ability to build and maintain satisfying relationships (Baglioni et al., 2010; Weinberg et al., 2016). The present study examined the interrelatedness of these concepts, examining emotion regulation as a moderator of the relationship between sleep and relationship satisfaction in a sample of 155 adults who were married or in long-term partnerships. Results indicated that both sleep and emotion regulation significantly predicted overall relationship satisfaction in the sample. Additionally, emotion regulation was found to significantly moderate the relationship between sleep and relationship satisfaction. Related implications, limitations, and directions for future research are addressed
Blenderized Tube Feeding Formulas: Attitudes, Barriers, and Clinical Benefits as Perceived by Registered Dietitians in Pediatric Care
Full text linkBlenderized tube feeding formulas (BTFF) are increasingly recognized as a viable alternative to conventional commercial tube feeding formulas (CTFF) for pediatric patients requiring enteral nutrition. This cross-sectional, exploratory study aimed to assess the experiences, attitudes, and perceived clinical benefits of BTFF use among Registered Dietitian Nutritionists (RDNs) working with gastrostomy-tube-dependent pediatric populations in the United States. A total of 146 RDNs completed a 45-item online survey, which gathered quantitative and qualitative data on BTFF familiarity, feasibility, clinical outcomes, caregiver factors, and institutional barriers. Findings revealed that while BTFF use remains variable across clinical settings, 55.8% of RDNs reported increased utilization over the past three to five years. Respondents identified key clinical benefits of BTFF, including improved gastrointestinal tolerance (53.7%), reduced symptoms (48.3%), and enhanced nutritional satisfaction (38.8%). Despite this, concerns related to food safety, nutrient adequacy, and preparation burden persist. RDNs with specialized training or certifications demonstrated significantly higher self-efficacy in BTFF-related knowledge, particularly in areas of preparation, delivery, and patient tolerance. Familiarity and comfort levels were notably higher among outpatient practitioners compared to those in hospital settings. Barriers to BTFF implementation were primarily practical in nature, with preparation time (71.2%), lack of caregiver knowledge (57.5%), and financial/resource constraints (53.4%) cited as top concerns. Most RDNs (65.3%) agreed that professional education programs could improve BTFF adoption, and over half (53.1%) supported interdisciplinary training for broader healthcare teams. The study also highlighted the need for standardized BTFF resources, such as food safety guidance and recipe protocols, to support safe and effective implementation. This research underscores the importance of comprehensive RDN training, institutional support, and family-centered education in optimizing BTFF use. Findings contribute to the growing evidence base that may inform future clinical guidelines, policy development, and research on the integration of whole-food enteral nutrition in pediatric care
Eating Habits, Eating Behavior Mediators, Body Composition and Physical Fitness among ROTC Cadets
Full text linkThe physical and mental demands of the military and the requirement to maintain body composition standards make healthful eating essential to military service. Reserve Officer Training Corps (ROTC) cadets are a unique subgroup of the United States military, and the combined demands of their military training and educational pursuits may increase their susceptibility to unhealthy eating patterns. The purpose of this study is to describe the relationship between eating habits, eating behavior mediators, body composition, and physical fitness among ROTC cadets. This study used a cross-sectional design that included an online survey, an inperson body composition assessment, and carotenoid measurements via the Veggie Meter. A purposive, convenience sample of ROTC cadets was recruited via word-ofmouth, flyers, a Louisiana Tech campus-wide email, as well as in-person during weekly ROTC meetings on Grambling State University’s campus. The online survey was created using scales from the Military Eating Behavior Survey (MEBS) to measure a) eating habits (i.e., satiety, cravings, hunger, restraint, emotional eating, meal pattern, healthy eating index-7 [HEI-7], general health supplement use, and performance supplement use), b) eating behavior mediators (i.e., perceived stress, sleep habits, concern with military image, agreement with ideal military physique, satisfaction with body shape, military body image) and c) physical fitness (i.e., self-reported physical fitness test scores). The survey was distributed to students via Qualtrics Survey Software. All ROTC members from Louisiana Tech University and Grambling State University who did not have an injury, pacemaker, and who were not pregnant were eligible to participate. Statistical analyses included frequencies and means with standard deviations and Pearson’s correlation analyses. The sample (n = 20) was predominantly male (90%) and between 18-22 years of age (75%). Sixty percent of the cadets were white, non-Hispanic, and 40% were African American or black. Of the cadets, 70% were in the Army ROTC program and 30% were in the Air Force ROTC program. Body composition analyses were completed on 15 cadets. The mean body mass index (BMI) was 24.34 kg/m2 (SD = 2.85), the mean percent body fat was 14.19% (SD = 7.63), and the mean visceral fat area was 45.89 cm2 (SD = 34.37). Carotenoid levels averaged 247.68 units (SD = 67.62). Skeletal muscle mass was strongly correlated with two eating behavior scale scores, food cravings scale scores (r = .66, p \u3c .01) and eating past fullness scores (r = .66, p \u3c .01). Emotional eating was correlated with food craving scale scores (r =.52, p \u3c .05) and strongly correlated with satiety scale scores (r = .64, p \u3c .01). General health supplement scale scores and performance supplement scale scores were correlated with HEI-7 scores (r = .56, p \u3c .05 and r = .57, p \u3c .05, respectively). Correlations between body composition measures and scale scores for hunger, restraint, emotional eating, meal pattern, and HEI-7 were non-significant. Perceived stress was correlated with both percent body fat (r =.57, p \u3c .05) and visceral fat (r =.60, p \u3c .05) as well as with scale scores for sleep habits (r = -.49, p \u3c .05), meal patterns (r = -.57, p \u3c .01), agreement with ideal military physique (r =.55, p \u3c .05), satisfaction with body shape (r =.60, p \u3c .01), and military body image (r =.63, p \u3c .01). Percent body fat and visceral body fat were highly correlated (r = .95, p \u3c .01). Percent body fat was correlated with scale scores for agreement with ideal military physique (r =.54, p \u3c .05), satisfaction with body shape (r =.58, p \u3c .05), and military body image (r =.52, p \u3c .05). There were negative correlation found between percent body fat and total Army Combat Fitness Test (ACFT) scores (r = -.81, p \u3c .05) and percent body fat and total Air Force Physical Fitness (AFPF) scores (r = -.98, p \u3c .01). Visceral fat was also correlated with both ACFT score (r = -.83, p \u3c .05) and AFPF (r = - .96, p \u3c .01). A positive correlation was found between sleep habits and HEI-7 scores (r =.50, p \u3c .05) as well as between sleep habits and meal pattern scores (r =.63, p = \u3c .05). Among this sample of ROTC cadets, numerous associations were observed among the various measures of eating habits, eating behavior mediators, body composition, and physical fitness. In particular, body composition was associated with physical performance, and perceived stress was related to body composition as well as several mediators of eating behavior. These results suggest that managing mental health and striving for optimal nutrition are essential to supporting body composition and the performance and health of military service members. Although additional research is needed to confirm these results, the present findings suggest the need for future studies to determine the best way to educate and support ROTC cadets to provide a holistic approach to help them achieve and maintain optimal mental and physical health at the start of their military careers
Using Stable Isotope Analysis to Investigate the Trophic Ecology of Aquatic Insects
Full text linkDespite their abundance on the landscape, ponds and associated macroinvertebrate assemblages have largely been underrepresented in scientific studies, which usually focus on lakes or streams. Similar to other waterbodies, ponds can harbor high levels of invertebrate biodiversity, which is important as aquatic insects are experiencing declines due to habitat destruction, pollution, climate change, and invasive species introductions. To evaluate how these threats impact pond insects and the ecosystem services they may provide, a thorough understanding of their ecology is essential. However, significant knowledge gaps remain, especially regarding trophic levels and species-specific diets. To address these knowledge gaps, I used carbon and nitrogen stable isotopes to estimate the trophic level and diet of common pond macroinvertebrates. I predicted that most of the taxa would be predators and that the backswimmer (Notonecta irrorata) would be the top predator. Results from three ponds estimated that most species ranged from trophic level 2-2.6 (primary consumer to omnivore), while one species of predaceous diving beetle (Thermonectus basillaris basillaris) had the highest trophic position at 4.03 (tertiary predator), surpassing the predicted top predator, the backswimmer (Notonecta irrorata), at 2.61. The diet of the analyzed taxa did not meet predictions and was widely varied. These results provide novel estimates of trophic level and diet for macroinvertebrates at the species level and contribute to our understanding of trophic dynamics in ponds
An Exploratory Case Study of a Community Food Pantry in Northwest Louisiana
Full text linkMany individuals are struggling with food insecurity in Louisiana; according to the Louisiana Food Bank Association\u27s website, Feeding Louisiana’s 2023 impact report, an estimated 683,100 people in Louisiana experience food insecurity. In northwest Louisiana, 30% of the population lives below the poverty line, with an average income of $34,485 per household. Common Ground is a nonprofit community outreach program in Northwest Louisiana, specifically Shreveport. The program has been in operation for over 20 years and strives to provide a place free of judgment and a place of common ground for those in the Cedar Grove community. Each week, they have a variety of programs for both children and adults, in addition to a community meal and the opportunity to access their food pantry (Common Ground, n.d.). All service organizations were strained during the COVID-19 pandemic as they are in other crises such as natural disasters. This research project sought to reflect on the experiences of this organization, the challenges encountered and the strategies it employed to provide supplemental foods to the community during the COVID-19 pandemic periods. It is not unusual in the best of times for these organizations to report financial constraints, limited storage for food, limited volunteer labor and needed connectedness with the clients (Cahill et al., 2017; Vaterlaus et al., 2018). The challenges, process changes, delivery of services, and organizational resilience were explored. Many food system changes, including food access and delivery during the pandemic, resulted in many strategic changes for service organizations, particularly feeding the food insecure in the community. Organizations needed to make quick adjustments to operational process, some were temporary others were retained after the pandemic. Case studies such as this one may assist organizations in reflecting on the actions taken during times of stress, such as natural disasters and pandemics in order to prepare for future stressors and by building successful strategies and resilience. The specific objectives of this retrospective case study included 1) determining the changes in the community meals served and the pounds of food distributed via the food pantry before, during, and after the COVID-19 pandemic using retrospective organizational data, 2) conducting an analysis of the management strategies for serving meals and operating the food pantry using in-depth interviews with key management personnel. This organization\u27s quantitative data was used to support key informant interview responses. Data collection commenced following approval from the Common Ground organization and the Louisiana Tech Institutional Review Board (IRB 25-025). The quantitative data chosen for this study was documented during June, July, and August during the years 2019, 2021, and 2023. The year 2019 represented the pre-pandemic period, 2021 represented the occurrence of the pandemic, and 2023 represented the post-pandemic period. Semi-structured interviews were conducted with the organization\u27s Chief Executive Officer (CEO), the grant writer, and five long-term volunteers. Data indicated an increased need in the community, as the pounds of food distributed were significantly higher during COVID-19 compared to the pre-COVID-19 period. This may be related to job loss, not being eligible for SNAP initially and the period of time it took to receive approval for support, or having reached the maximum amount of benefits that did not fully meet the needs of the household (Pandemic Unemployment Insurance Provisions; n.d.). The pounds of food distributed post-COVID remained higher than the pre-COVID number. This could be related to the extended time it took for community members to recover financially when returning to work, those taking part-time jobs, having only one worker in the household when previously there were two, and returning to work at lower paying jobs. The number of households served at the food pantry also experienced interesting trends. The number of households served at the food pantry was the highest during the pandemic and the lowest during the post-pandemic period. One explanation for this could be that the Common Ground food pantry was distributing an increased amount of food to a smaller amount of households. The number of community meals served post-pandemic was slightly higher than those served during the pandemic and was substantially higher than the pre-pandemic months. The pandemic introduced new households to the services provided by Common Ground and more may have been accessing the community meal in addition to the food pantry services. The financial recovery time may also have impacted the use of the meal service. An additional explanation for the increase in the community meal attendees could be the community\u27s excitement and need to engage with their community post-pandemic. The interviewees confirmed that new community members who engaged with Common Ground during COVID-19, stayed engaged with Common Ground after COVID-19. The consistency of the program and its volunteers may have contributed to developing the relationships with the clients, which extended client engagement. Additionally, the ability to engage in relationships with others in similar circumstances and feel welcomed by the volunteers might have aided the community members in not feeling embarrassed or shame when accessing these types of services for the first time in their lives. When interviewees were asked what they would recommend to other organizations going through crisis situations, the majority stated they would advise them to simply be flexible and lead with consistency and compassion. They also reported that listening to their community was an essential part of their management strategy so they could quickly adjust processes to meet their needs. The immediate issue was to adjust their process for receiving the large amounts of food needed from a large food bank organization. This meant there was a need to address the food storage issue. One way to prepare for this problem is to consider purchasing or leasing temporary storage for dry or perishable goods and to identify alternate storage sites within the organization. Perhaps some rooms used for congregating could be temporarily used for storage. A plan in place prior to a crisis for food storage can be essential. It was also noted that the volunteers did not receive formal training regarding food safety or creating food boxes or in this case infection control measures. Offering formal training to volunteers would increase efficiency and aid in any confusion that could occur during a crisis. Having the organization develop a written plan for crises and training multiple people on this plan is essential. As with COVID-19, in organizations with very few paid staff, all need to be cross-trained, as key employees or volunteers may have become unable to perform duties due to illness. All organizations could also benefit from communicating with other organizations to create a collaborative plan for emergencies to reduce redundancy of effort. As this organization had an extended reach into the community, it was able to draw upon new volunteer labor. This should be modeled in a collaborative, community plan for future crises. In volunteer-based organizations, the toll on the volunteers can be great if the workload and duties are greatly increased. This was seen in this organization. For example, original efforts at meeting community needs extended past what volunteers could provide and had to be reduced to a manageable level, although still higher than the pre-pandemic period. This organization was nimble enough with adequate resources to move their pantry and community meal services outdoors. Because they owned property near the building, they were able to open two car lines to distribute food. Common Ground had an increased presence on social media, which continued after this experience. The car lines to pick up food boxes also served as marketing for the programs. Volunteers noted that this might have given them some of the new clients, as well as new clients spreading news of the services by word-of-mouth. Future work with volunteer organizations could focus on assisting with development of emergency procedures and strategies for management during crises. Assisting these organizations with finding resources for policies and best practices is essential. It may benefit these organizations to seek like organizations to reflect on their experiences and their management strategies to inform them of the development of crisis plans specific to them. Future research could investigate and document the reasons for continued high levels of access to needed services. This would enable researchers to study the factors that most effected food needs during the pandemic in order to plan for mitigation
Secret Key Generation Based on the Physical Layer Characteristics for IoT Networks
No full textThe rapid expansion of low-resource devices, coupled with advances in telecommunications, has significantly increased the number of connected devices and enabled the development of affordable, energy-efficient, portable, and high-performance sensors for diverse applications. However, this convenience comes with security and privacy concerns related to the reliability of hardware, software, and communication infrastructure. The extensive interconnectivity of limited-resource devices and the transmission of large data volumes pose significant security challenges in wireless networks. The future wireless technologies, such as 5G, will enable the transfer of critical data, including personal, financial, military, and industrial information, necessitating secure communication in wireless networks. Generally, security can be achieved through classical cryptography or physical layer security. Classical cryptography techniques and their associated protocols are commonly used to secure data transfers and distribute encryption keys. Nevertheless, in highly constrained environments, these algorithms are costly and inefficient to implement, thus unsuitable for providing cryptographic solutions. They introduce many challenges, including resource consumption and the management and distribution of keys to diverse resource-constrained devices. On the other hand, recent research has focused on leveraging the reciprocity and unpredictability of wireless fading channels for physical-layer security, enabling the generation of symmetric cryptographic keys that safeguard transmissions between two entities. However, current techniques are plagued by high bit-disagreement rates and poor randomness in the generated bits. In addition, cryptographic hash algorithms ensure the preservation of data integrity, even as attackers’ computational capabilities continue to advance. Lightweight cryptographic hash functions, a less complex variant of existing techniques, effectively address the challenges of securing communication in constrained devices, such as RFIDs and sensors, as well as in devices with abundant resources that interact with them, including machine-to-machine, machine-to-device, and device-to-device communication. Their applicability extends to other domains with similar characteristics. Therefore, this work introduces an improved quantization algorithm and a lightweight hash function for the physical-layer security protocols. The proposed key generation scheme was benchmarked using the NIST randomness test suite and compared against existing approaches. Additionally, the hash function was evaluated to assess its implementation cost, efficiency, and security properties. The analysis results demonstrate that the proposed hash function achieves excellent performance across multiple metrics
Real-Time Prediction of Dynamical Systems Using a Hybrid Analog Computer: Network Traffic Modeling
Full text linkAs the number of online users grows exponentially, the number and severity of cyber threats escalate, urgently requiring advancements in real-time network modeling and response. Swiftly predicting and analyzing network traffic is crucial for effective network monitoring and control, preventing cyber breaches, and maintaining healthy network functionality. This research presents a novel approach to real-time modeling based on analyzing evolving properties and patterns in a dynamical network system using a hybrid analog-digital computer. An analog computer was utilized as a co-processor to compute differential equations that model the Transmission Control Protocol (TCP) window size. A comparative analysis was conducted between the digital model, using Euler’s numerical integration method, and the hybrid model. Based on the Median Absolute Percent Error (MedAPE) statistical metric, the digital model attains a 98.87% accuracy in predicting TCP window size, while the hybrid model achieves 91.85% accuracy, excluding the precision loss from the pre-processed input signals. The hybrid model demonstrated a 570% improvement in execution time performance compared to the digital model, proving superior speed with minimal sacrifice on accuracy. The analysis further compares linear and nonlinear dynamical approaches, including Model Predictive Control (MPC), frequency-domain techniques, and Ordinary Differential Equations (ODEs), underscoring the hybrid system’s speed advantage, particularly for complex, real-time applications. The findings establish hybrid analog-digital systems as a potent alternative for dynamic network traffic modeling, providing a foundation for broader applications in nonlinear dynamical systems
Smoothed Particle Hydrodynamics for Free-Surface Flows and Time Series Forecasting Approach for Computational Fluid Dynamics
Full text linkWith the increase in computing power, numerical simulation has become an essential approach to solving problems in engineering and science. Numerical simulations provide a platform for theoretical validation and facilitate novel discovery. Even though extensive mesh-based numerical methods are utilized, significant limitations exist, particularly in Computational Fluid Dynamics (CFD). Because of the grid distortion, issues related to large deformations, moving interfaces, and free surfaces may lead to considerable computational errors, constraining their efficacy in numerous applications. As a mesh-free method, Smoothed Particle Hydrodynamics (SPH) was introduced in 1977 and has been widely applied in many fields such as astrophysics and hydrodynamics (D. a. Liu 2015). Free surface flow problems are covered in various domains, including hydraulic engineering, mechanical engineering, ship hydrodynamics, and petrochemical engineering. Hence, studying the free surface flow problem has theoretical and practical significance. Due to the advantages of SPH in handling large deformations and free boundaries, SPH is particularly suitable for free surface flow problems. Furthermore, new achievements in computational power improve computing efficiency; this enables SPH to simulate complex free surface flows. This dissertation studies the validation of SPH for free surface flow applications and explores a time series forecasting method to enhance CFD. There are four main contributions to this dissertation: First, we introduce artificial viscosity into SPH. In the meantime, this improved method is shown through demos of free surface flow in different cases. Second, based on the demos of the improved SPH method in Chapter 3, we discuss the water break models to explore the further application of SPH in complex coastal environments in Chapter 4. We also analyze the interaction between waves and various water break designs. Then, we assess the effects of different structures on wave overtopping to identify the optimal water break configuration. Third, we address the importance of water level research by examining water break models. In Chapter 5, with historical water level data from the Mississippi River, we discuss a time series analysis model based on ARIMA to forecast future water levels. The forecast results are in line with the actual trend. Finally, we show how GPU parallel computation dramatically improves the simulation efficiency of our model